The position that a prophet (al-nabi) is one who is granted inspiration in the form of revelation and is not commanded to convey it, and that a messenger (al-rasool) is a prophet who is granted revelation and commanded to convey what was revealed to him – this is not correct. Because Allah’s statement:

وَمَا أَرْ‌سَلْنَا مِن قَبْلِكَ مِن رَّ‌سُولٍ وَلَا نَبِيٍّ

And We did not send before you any messenger or prophet… [22:52]

– this statement demonstrates that both of them are sent (mursal), and along with that, that there is a distinction between the two of them.

1) a prophet who is also a messenger is one to whom a scripture and a distinct sharee’ah (divine legislation) are revealed along with miracles which thereby affirm his prophethood, and

2) that a prophet who is sent but is not a messenger is one to whom a scripture is not revealed, and he is only divinely inspired to call the people to the sharee’ah of a messenger prior to him, such as the prophets of the Banu Israa’eel who were sent and commanded to act according to what is in the Tawrah. This is as Allah clarified with His statement: